Newegg Shell Shocker. Newegg has the TP-LINK TL-WN721N 150Mbps Wireless N USB Adapter for a low $7.19 Free Shipping after 20% off Wireless Adapters Coupon Code: "EMCJNJJ28" (Exp 10/11). Tax in CA, NJ, TN. This is 38% ($5) less than the next best price from a reputable merchant.